PolyFromShape 接受类型为多边形的形状和 Spatial 参考系标识以返回多边形。
语法
db2gse.PolyFromShape (ShapePolygon Blob(1M), srs db2gse.coordref)
返回类型
db2gse.ST_Polygon
示例
该程序段填充 SENSITIVE_AREAS 表。 问号表示将在运行期检索的 ID、名称、大小、类型和区域值的参数标记。
除了包含 zone 列(用于存储公共设施的多边形几何图形)之外,SENSITIVE_AREAS 表还包含描述受威胁的公共设施的几列。
CREATE TABLE SENSITIVE_AREAS (id integer, name varchar(128), size float, type varchar(10), zone db2gse.ST_Polygon); /* Create the SQL insert statement to populate the id, name, size, type and zone. The question marks are parameter markers that indicate the id, name, size, type and zone values that will be retrieved at runtime. */ strcpy (shp_sql,"insert into SENSITIVE_AREAS (id, name, size, type, zone) values (?,?,?,?, db2gse.PolyFromShape (cast(? as blob(1m)), db2gse.coordref()..srid(0)))"); /* Allocate memory for the SQL statement handle and associate the statement handle with the connection handle. */ rc = SQLAllocStmt (handle, &hstmt); /* Prepare the SQL statement for execution. */ rc = SQLPrepare (hstmt, (unsigned char *)shp_sql, SQL_NTS); /* Bind the id integer value to the first parameter. */ pcbvalue1 = 0; rc = SQLBindParameter (hstmt, 1, SQL_PARAM_INPUT, SQL_C_INTEGER, SQL_INTEGER, 0, 0, &site_id, 0, &pcbvalue1); /* Bind the name varchar value to the second parameter. */ pcbvalue2 = name_len; rc = SQLBindParameter (hstmt, 2, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_CHAR, 0, 0, name, 0, &pcbvalue2); /* Bind the size float to the third parameter. */ pcbvalue3 = 0; rc = SQLBindParameter (hstmt, 3, SQL_PARAM_INPUT, SQL_C_FLOAT, SQL_REAL, 0, 0, &size, 0, &pcbvalue3); /* Bind the type varchar to the fourth parameter. */ pcbvalue4 = type_len; rc = SQLBindParameter (hstmt, 4, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_VARCHAR, type_len, 0, type, type_len, &pcbvalue4); /* Bind the zone polygon to the fifth parameter. */ pcbvalue5 = zone_len; rc = SQLBindParameter (hstmt, 5, SQL_PARAM_INPUT, SQL_C_BINARY, SQL_BLOB, zone_len, 0, zone_shp, zone_len, &pcbvalue5); /* Execute the insert statement. */ rc = SQLExecute (hstmt);